Objective:　With　the　development　of　marine　fishery,　the　output　of　low-value　fishes　increases　year　by　year.This　study　aimed　to　promote　the　commercial　value　of　low-value　fishes　by　biotechnology　and　develop　new　fish　fillets　with　good　gel　property　and　water　binding　capacity,　then　explore　its　preliminary　mechanism.　Methods:　With　gel　strength　as　selecting　index,　fish　fillets　were　prepared　from　surimi　of　low-value　fishes　and　SPI　by　TGase.　Single　factor　test　and　response　surface　were　used　to　obtain　optimum　formulation,　SDS-PAGE　and　Nuclear　Magnetic　Resonance　were　exerted　to　study　its　preliminary　mechanism.　Conclusion:　Optimal　conditions　for　setting　were　as　follows:　SPI　1.86%,　TGase　0.24%,　gelation　temperature　35　,　gelation　time　1.0　h.　The　results　showed　that　TGase　catalyzed　a　covalent　cross　link　between　FPI　and　SPI.　As　a　result,　there　was　a　stable　protein　super-molecules,　which　improved　gel　property　and　water　binding　capacity　of　fish　fillets.　©　2018,　Editorial　Office　of　Journal　of　CIFST.　All　right　reserved.